Grinding apparatus



Jan. 10, 1933. F. e. MUSHENO GRINDING APPARATUS Filed March 11. 1931 Z H I M M l l l l l l h H H H IN N HM 7 M QM M Q INVENTOR Patented Jan. 10, 1933 UNIT sures;

FRED e. MUSI-IENO, onscHUYLm L HAVEN, PENNSYLVANIA, ASSIGNOR TO, 5

ALLEGHENY sr'anr. COMPA Y, n'oonronarron or EENNSYLVANIA GRINDING .APPABA' TIJ'SV Application file d .March 11, 1931. Se1i al 1Io. 521, 649

This invention relates to, the grinding and/0r pollshing of metallic surfaces and varied applicationsfor their use. I Some applicatlons require thatthe 1nter1or surface,

of such tubing and pipe, be smooth.v and polished.

Usually the tubing, cylinders and pipe referred to above are made in relatively long lengths; therefore, the smoothing and polishing of the interior surfaces, thereofpresenta difficult problem because spec al grlnders are required to grind and polish these surfaces with uniformity. I Grinders for this class of work require holders for the abraslveelements or stones, so constructed that the grinding and polishing work may becarried out effectively, Provision mustbeinade also for thesupply vof sufficient liquidto the in, 3 terior of the pipe or tubing for cool'ingthe metal surfaces ground and to suitably lubri; cate the abraslve elements,

An object of this invention. is to provide an internal grinder for the aforesaid purpose that shall be simple in construction and efli- I I *may besuch as tobe substantiallyconcentric cient in operation 4 Another object of the invention is t0.pro-.

vide for supportingabrasive elements, such a as grinding stones, within pipe .or tubing and I yieldingly urging the elements or stones into engagement with surfaces to be ground and/or'polished.

And a further object of the invention is to provide a grinder, as set forth above, that :may be supplied with an adequate quantity of lubricating and cooling liquid while'the grinding and/or polishing operations are,

being performed.

Other objects of theinventionwill, in part, be apparent, and will,,in part, .be obvious from the following description taken in conjunction with the accompanyingdrawing, in

which Figure l is a fragmentary view, partly section, of a grinder arranged and constructed in accordance withan embodiment of the in- I vent1on;;

Fig. 2 is a fragmentary top plan View ofthe device shown in Fig. 1, parts thereof being removed;

Fig. 3'is an end view of a cylinder or tube-,

audit-he grinder shown in Fig. 1;

Fig. i is a fragmentary sectional viewtaken II on linefIV-IV of Fig. 3; and i Fig. 5 is a top plan view of a carriage, a tube 'or' pipe carried thereby,and the grinder asset up for grinding the interiorsurface of thepipe or tube.

Throughout thedrawing and the specificatiox i like. reference characters indicate like; parts.

Referring to the drawing, anninternalr grinder l is illustrated, adapted to be rotatably disposed .within the bore of a cylinder,

tube or pipe 2. They pipe may be supported on a carriage 3 arranged forreciprocating I travel. While the grinder is rotating or turiiing, the carriage ismoved back and forth over. the grinder, whereby the internalsurface of the pipe is ground and/or polished.

The grinderl comprises a mandrel having a body portion 7 and necks 8 9. Thebody portion of the mandrelis illustrated as having flat sides 10 and 11 and rounded or curved edges 12 and 13. The curvature'of the edges with the inside surface of thepip e or tube.

In practice it is preferred that the distance between the flat sides 10 and 11 bemateria lly less than the internal diameter of the pipe er tube SO' that ample space, as i ndiC atedat 14; and 1 5, may] be available for the reception in staggered relation, and spaced suitable distances apart.

In order that pockets or recesses may be formed in conjunction with notches 16, plates 17 and 18 are secured to the sides of the body portion; rivets 19, or other suitable means, being employed to hold the plates in place. Abrasive elements or stones 20 are movably disposed in the pockets, formed as aforesaid. The abrasive elements or stones may be rectangular in transverse section having grinding arcs the lengths of which are designated by dimension L (see Fig. 2).

In order that the abrasive elements or stones may be yieldingly urged outwardly of the pockets and into engagement with the internal surface of the tube or pipe to be ground, a spring 21, preferably a coil spring, is mounted in each. pocket between the bottom thereof and the abrasive element or stone. Each spring may be disposed in a recess 22 formed in each pocket. The tension of the springs may be such as will cause the abrasive elements to bear upon the surface to be ground at the desired or proper pressure.

In order that the mandrel may be centrally supported within the pipe or tube, bearings 23 are mounted on the necks of the mandrel, and suitable clearance may be provided to permit turning of the necks therein. The bearings may be of any suitable material and for this purpose babbit of suitable quality may be used.

To prevent longitudinal movement of the bearings 23 on the necks of the mandrel, collars 24 and 25 may be mounted on the necks at the outer ends of the bearings. Set screws 26 may be employed to hold the collars in place.

In order that liquid, for the aforementioned purpose, may be supplied to the surfaces of the pipe or tubing being ground by the abrasive elements, a passageway 27 may be formed in one or the other of the mandrel necks; as illustrated this passageway is formed in neck 9. Passageway 27 terminates in branch passageways 28 and 29 that run to the surface of the body portion of the mandrel (see Figs. 1, 2 and 4).

In operation, grinder 1 is attached to a shaft 30 which is long enough to permit the full length of the pipe or tube to traverse the abrasive elements carried by the body portion of the mandrel. When shaft 30 is of such length, only one grinder is required and it operates from one end of the tube or cylinder being ground and/or polished, (see Fig. 5).

If the tubes, pipes or cylinders operated upon, are too long, or in case, it is desired to increase the rate of grinding and/or polishing, two grinders may be employed, one operatibng from each end of the pipe, cylinder or tu e.

As shown in Figs. 1 and 5, shaft 30 is hollow, as at 31, and coupled to the mandrel by collar 25 held fast to mandrel neck 9 and the shaft by the set screws 26. The shaft passageway 31 communicates with mandrel passageway 27, so that liquid, of any known and suitable composition, or quality, may be forced into the shaft to the mandrel passageways. Shaft passageway 31 may be connected to a liquid supply pipe 32.

The grinding operation and the manner in which the grinder is utilized may best be understood with reference to Fig. 5. A pipe, tube or cylinder 2 is mounted in collars or supports 33 of the carriage. The carriage, as shown, is merely a diagrammatic illustration of a means for moving the tube, cylinder or pipe carried thereby, back and forth along the grinder.

The carriage may embody racks 34 and pinions 35; the pinions being driven by pulleys 36 carried by a shaft 37, belts 38 and pulleys 39 mounted on shafts 40. The pinions, as shown, may be carried by the shafts 40.

In order that the carriage may be driven back and forth, that is reciprocatingly, a reversing motor 41 is provided and connected to shaft 36 which in turn is connected by a pulley P and belt 38 or any other suitable driving mechanism, to shaft 37.

As shown in Fig. 5, the shaft 30 and grinder 1 may be driven by a motor 42 coupled to the shaft by a belt 43 and a pulley 44.

The specific form of carriage employed to move the pipe, tubes or cylinders over the grinder may be modified, altered and changed so as to suit the particular conditions encountered.

After the pipe, tube or cylinder has been mounted on the carriage, the carriage is moved towards the grinder until neck 8 is within the bore of the tube, cylinder or pipe (see Fig. 4). The abrasive elements or stones are then depressed into their respective pockets to provide sufficient clearance between the grinder and the interior surface of the pipe. When all of the abrasive elements are within the bore of the object to be ground and/or polished, motor 42 is set in operation to turn the mandrel at the speed required for the quality and rate of grinding and polishing desired; also the carriage motor is set in operation to move the tube, cylinder or pipe, at the proper speed, along the grinder. \Vhile the grinding of the internal surfaces is in progress, liquid is supplied to such surfaces to lubricate the abrasive elements at the arcs thereof, and to cool the metal being cut away thereby.

While various modifications and changes may be made in the grinder herein disclosed without departing from the spirit and the scope of the invention, it is to be understood that only suchlimitations shall be placed on the invention as are imposed by the prior art and the appended claims.

by Letters Patent is:

WVhat I claim as new and desire to secure 1. An internal grinder for objects, such as tubes, cylinders and the like, comprising a mandrel of smaller diameter than the bore in said objects, said mandrel having at least one flat side and curved edges, said curved edges having pockets therein normal to the longitudinal axis of said mandrel, abrasive elements in said pockets, and means in said pockets urging said elements outwardly therefrom and into engagement with the surface to be ground.

2. An internal grinder for objects, such as tubes, cylinders and the like, comprising a mandrel adapted to be received within the bore of said objects, said mandrel having pockets therein normal to the longitudinal axis thereof, abrasive elements in said pockets, means in said pockets urging said elements outwardly, and a iassageway in said mandrel terminating at the surface thereof for the passage of liquid to the surfaces being ground.

8. An internal grinder comprising a rotatable mandrel having a body portion with flat sides and curved edges and necks at the opposite ends thereof, the distance between the sides bein less than the distance between the edges, said body portion having notches therein normal to said edges, Jlates secured to the sides of said body portion thereby closing the sides of said notches to form pockets, abrasive elements in the pockets and means normally urging said elements outwardly therefrom.

4. An internal grinder comprising a rotatable mandrel having a body portion with flat sides and curved edges and necks at the opposite ends thereof, the distance between the sides being less than the distance between the edges, said body portion having notches therein normal to said edges, abrasive elements in said notches, means in said notches urging said elements outwardly and means secured to the flat sides of the mandrel to provide lateral support for the abrasive elements.

5. An internal grinder comprising a rotatable mandrel having a body portion with flat sides and curved edges and necks at the opposite ends thereof, the distance between the sides being less than the distance between the edges, said body portion having notches therein normal to said edges, abrasive elements in said notches, means in said notches urging said elements outwardly, means secured to the fiat sides of the mandrel to pro- .vide lateral support for the abrasive elements and a passageway in one of said necks having outlets at the surface of said body portion through which liquid may be conveyed to the surfaces to be ground by said abrasive elements.

6. An internal grinder comprising a retatable mandrel having a body portion with flat sides, and curved edges and necks at the opposite ends thereof, the distance between the sides being less than the distance between the edges, said body portion having notches therein normal to said edges, abrasive elements in said notches, means in said notches urging said elements outwardly, means secured to the fiat sides of the mandrel to provide lateral support for the abrasive elements, a passageway in one of said necks having outlets at the surface of said body portion through which liquid may be conveyed to the surfaces to be ground by said abrasive elements and guide members on said necks to centrally locate said mandrel with the bore of an object, the surface of which is being ground.

7. An internal grinder comprising a rotatable mandrel having a body portion with flat sides and curved edges and necks at the opposite ends thereof the distance between the sides being less than the distance between the edges, said body portion having notches therein normal to said edges, plates secured to the sides of said body portion thereby closing the sides of said notches to form pockets, abrasive elements in the pockets, and means normally urging said elements outwardly therefrom and guide members on said necks to centrally locate said mandrel with the bore of an object, the surface of which is being ground.

8. An internal grinder comprising a rotatable mandrel having a body portion with flat sides and curved edges and necks at the opposite ends thereof, the distance between the sides being less than the distance between the edges, said body portion having notches therein normal to said edges, abrasive elements in said notches, means in said notches urging said elements outwardly, means secured to the flat sides of the mandrel to pro vide lateral support for the abrasive elements and guide members on said necks to centrally locate said mandrel with the bore of an object, the surface of which is being ground.

9. An internal grinder for objects, such as tubes, cylinders and the like, comprising a mandrel over and along which said objects may move relative to the mandrel, said mandrel having spaced oppositely disposed pockets arranged in staggered relation along. said mandrel, abrasive elements in said pockets, means in said pockets yieldingly urging said abrasive elements outwardly, and guide members at each end of the mandrel arranged to centrally locate the same withinsaid objects.

10. An internal grinder for tubes, cylinder and the like, comprising a mandrel having a body portion and necks at the ends of the body portion,.the breadth of said body portion being slightly less than the internal diameter of said tubes, cylinders and the like, and its thickness being less than said internal diameter thereby providing a space of substantial "olume between each side of said body portion and the adjacent wall surface of said tubes, cylinders and the like for the reception of liquid, said body portion having pockets formed in the opposite edges thereof, abrasive elements in said pockets, and means in said pockets yieldingly urging said elements outwardly.

11. An internal grinder for tubes, cylinders and the like, comprising a mandrel having a body portion and necks at the ends of the body portion, the breadth of said body portion being slightly less than the internal diameter of said tubes, cylinders and the like, and its thickness being less than said internal diameter thereby providing a space of substantial volume between each side of said body portion and the adjacent wall surface of said tubes, cylinders and the like for the reception ofliquid, said body portion having pockets formed in the opposite edges thereof, abrasive elements in said pockets, and coil springs in said pocket-s yieldingly urging said elements outwardly.

12. An internal grinder for tubes, cylinders and the like comprising a mandrel having a body portion and necks at the ends of the body portion, the breadth of said body portion being slightly less than the internal diameter of said tubes, cylinders and the like, and its thickness being less than said internal diameter thereby providing a space of substantial volume between. each side of said body portion and the adjacent wall surface of said tubes, cylinders and the like for the re ception of liquid, said body portion having pockets formed in the opposite edges thereof, abrasive elements in said pockets, means in said pockets yieldingly urging said elements outwardly and guide members carried by said necks to centrally locate the mandrel within said tubes, cylinders and the like.

13. An internal grinder for tubes, cylinders and the like, comprising a mandrel hav ing a body portion and necks at the ends of the body portion, the breadth of said body portion being slightly less than the internal diameter of said tubes, cylinders and the like, and its thickness being less than its breadth thereby providing a space between each side of said body portion and the adjacent wall surface of said tubes, cylinders and the like for the reception of liquid, said body portion having pockets formed in the opposite edges thereof, abrasive elements in said pockets, means in said pockets yieldingly urging said elements outwardly anda passageway in one of said necks terminating in discharge ports formed in the body portion through which liquid may be conveyed to the space between 

